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arXiv 2408.07261math.NAcs.NA
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一类非局部扩散问题的惩罚间断Galerkin方法的数值分析

Numerical analysis of a class of penalty discontinuous Galerkin methods for nonlocal diffusion problems

Qiang Du, Lili Ju, Jianfang Lu, Xiaochuan Tian

AI总结:

针对一维非局部扩散问题解可能含间断的特点,提出带不同惩罚项的间断Galerkin方法,证明其稳定性、误差估计与渐近相容性,通过数值实验验证了算法性能与理论结论。

摘要:

本文研究了一类用于求解一维非局部扩散(nonlocal diffusion, ND)问题的间断Galerkin(discontinuous Galerkin, DG)方法。作为积分方程的非局部模型被广泛用于描述众多具有长程相互作用的物理现象。ND问题是经典扩散问题的非局部对应形式,当相互作用半径(视界,horizon)趋于零时,非局部性消失,ND问题收敛于经典扩散问题。在特定条件下,ND问题的精确解可能呈现间断性,这是它与经典扩散问题的区别所在。过去几十年间,DG方法在计算流体力学领域处理含间断的问题时展现出显著优势,因此自然可以采用DG方法来求解ND问题。基于[Du-Ju-Lu-Tian-CAMC2020]的研究,我们开发了带有不同惩罚项的DG方法,确保所提出的DG方法在视界趋于零时存在局部对应形式。这表明当视界趋于零时,所提方法会收敛于已有的DG格式,这对于实现渐近相容性至关重要。本文提供了严格证明,以论证所提DG格式的稳定性、误差估计和渐近相容性。为了观察非局部扩散的效应,我们还考虑了带非局部扩散的含时对流扩散问题。我们开展了多项数值实验,包括精度测试以及带非局部扩散的Burgers方程实验,并采用了多种不同的视界参数,以证明所提算法的良好性能并验证理论结果。

英文摘要:

In this paper, we consider a class of discontinuous Galerkin (DG) methods for one-dimensional nonlocal diffusion (ND) problems. The nonlocal models, which are integral equations, are widely used in describing many physical phenomena with long-range interactions. The ND problem is the nonlocal analog of the classic diffusion problem, and as the interaction radius (horizon) vanishes, then the nonlocality disappears and the ND problem converges to the classic diffusion problem. Under certain conditions, the exact solution to the ND problem may exhibit discontinuities, setting it apart from the classic diffusion problem. Since the DG method shows its great advantages in resolving problems with discontinuities in computational fluid dynamics over the past several decades, it is natural to adopt the DG method to compute the ND problems. Based on [Du-Ju-Lu-Tian-CAMC2020], we develop the DG methods with different penalty terms, ensuring that the proposed DG methods have local counterparts as the horizon vanishes. This indicates the proposed methods will converge to the existing DG schemes as the horizon vanishes, which is crucial for achieving asymptotic compatibility. Rigorous proofs are provided to demonstrate the stability, error estimates, and asymptotic compatibility of the proposed DG schemes. To observe the effect of the nonlocal diffusion, we also consider the time-dependent convection-diffusion problems with nonlocal diffusion. We conduct several numerical experiments, including accuracy tests and Burgers' equation with nonlocal diffusion, and various horizons are taken to show the good performance of the proposed algorithm and validate the theoretical findings.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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